Splitwise

Splitwise is an expense-sharing and bill-splitting service that helps roommates, travel groups, couples, and friends track shared costs and settle up fairly. Its public Self-Serve REST API (v3.0) lets third-party applications read and manage a user's groups, friends, expenses, comments, and notifications on that user's behalf, authenticating with OAuth 2.0 or a personal API key. Splitwise was added to the API Evangelist network from a venture-capital portfolio lead and has been enriched from its public developer documentation and OpenAPI specification.

Splitwise publishes 7 API contracts indexed on the APIs.io network, including Comments API, Expenses API, Friends API, and 4 more. Tagged areas include Company, Consumer, Expense Management, Personal Finance, and Bill Splitting.

The Splitwise catalog on APIs.io includes 1 Spectral governance ruleset.

Splitwise’s developer surface includes authentication, documentation, API reference, signup flow, engineering blog, and 22 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

40.5/100 developing ▬ flat Agent 28/100 agent aware Front door AI 1/6 silent Heartbeat 87/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract 2 Agent Skills

Company Consumer Expense Management Personal Finance Bill Splitting Payments REST API OAuth Authentication

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 40.5/100 · developing

Contract Quality 8.6 / 19

Developer Ergonomics 6.3 / 15

Access Clarity 5.1 / 15

Operational Transparency 1.8 / 10

Contract Governance 1.6 / 9

Discoverability 5.5 / 8

Regulatory Posture 5.5 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 28/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document

6 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 45.7 — up to +13.6 composite points
Access Clarity scores 34.2 — up to +13.2 composite points
Developer Ergonomics scores 42.3 — up to +11.5 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/splitwise/apis.yml: open an issue on github.com/api-evangelist/splitwise to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Raycast Store Extensions (first-party publishers + community-wrapped products)	covered	14.6	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OAuth

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

OpenAPI

measured — observed by APIs.io (published)

OAuth 2.0

measured — observed by APIs.io (declared)

APIs 7

Individual APIs this provider publishes, each with its own machine-readable definition.

Splitwise Comments API

The comments API from Splitwise — 3 operation(s) for comments.

Splitwise Expenses API

The expenses API from Splitwise — 6 operation(s) for expenses.

Splitwise Friends API

The friends API from Splitwise — 5 operation(s) for friends.

Splitwise Groups API

A Group represents a collection of users who share expenses together. For example, some users use a Group to aggregate expenses related to a home. Others use it to represent a t...

Splitwise Notifications API

The notifications API from Splitwise — 1 operation(s) for notifications.

Splitwise Other API

The other API from Splitwise — 2 operation(s) for other.

Splitwise Users API

Resources to access and modify user information.

Scroll for all 7

Open Collections 7

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Splitwise comments API

OPEN COLLECTION

Splitwise comments expenses API

OPEN COLLECTION

Splitwise comments friends API

OPEN COLLECTION

Splitwise comments groups API

OPEN COLLECTION

Splitwise comments notifications API

OPEN COLLECTION

Splitwise comments other API

OPEN COLLECTION

Splitwise comments users API

OPEN COLLECTION

Scroll for all 7

Agent Skills 2

Packaged agent skills for driving this provider's APIs from an AI assistant.

splitwise-check-group-balances

AGENT SKILL

splitwise-log-shared-expense

AGENT SKILL

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Splitwise

SLA

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Splitwise API Rules

56 rules · 51 errors 1 warnings 4 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Splitwise Api Overlay

3 actions · update · splitwise-openapi.json

GENERATED

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Splitwise Authentication

http/oauth2 · 2 schemes

SECURITY

Splitwise Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Splitwise Vulnerability Disclosure

security.txt · contact published

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Splitwise Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

SignUp

SignUp

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

LLMsTxt

AgentSkill

WellKnown

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

DataModel

Conformance

Lifecycle

Build 1

SDKs, sample code, and the tooling you integrate with

Packages

Packages

Access & Security 6

Authentication, authorization, and security posture

Authentication

Authentication

OAuthScopes

OAuthScopes

SecurityTxt

SecurityTxt

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

StatusPage

StatusPage

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

BlogRSS

BlogRSS

Blog

Blog

Website

Website

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: splitwise
name: Splitwise
description: Splitwise is an expense-sharing and bill-splitting service that helps roommates, travel groups, couples, and
  friends track shared costs and settle up fairly. Its public Self-Serve REST API (v3.0) lets third-party applications read
  and manage a user's groups, friends, expenses, comments, and notifications on that user's behalf, authenticating with OAuth
  2.0 or a personal API key. Splitwise was added to the API Evangelist network from a venture-capital portfolio lead and has
  been enriched from its public developer documentation and OpenAPI specification.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://www.splitwise.com/assets/press/logos/sw.svg
url: https://raw.githubusercontent.com/api-evangelist/splitwise/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- bullpen-capital
- insight-partners
- matrix-partners
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-10-06'
x-docs-platform: redocly
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
x-docs-hosting: github-pages
tags:
- Company
- Consumer
- Expense Management
- Personal Finance
- Bill Splitting
- Payments
- REST API
- OAuth
- Authentication
tags_raw:
- Company
- Consumer
- Expense Management
- Personal Finance
- Bill Splitting
- Payments
- REST API
- OAuth
- Authentication
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: splitwise:splitwise-comments-api
  name: Splitwise Comments API
  description: The comments API from Splitwise — 3 operation(s) for comments.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - Comments
  tags_raw:
  - comments
  properties:
  - type: OpenAPI
    url: openapi/splitwise-comments-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-expenses-api
  name: Splitwise Expenses API
  description: The expenses API from Splitwise — 6 operation(s) for expenses.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - Expenses
  tags_raw:
  - expenses
  properties:
  - type: OpenAPI
    url: openapi/splitwise-expenses-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-friends-api
  name: Splitwise Friends API
  description: The friends API from Splitwise — 5 operation(s) for friends.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - Friends
  tags_raw:
  - friends
  properties:
  - type: OpenAPI
    url: openapi/splitwise-friends-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-groups-api
  name: Splitwise Groups API
  description: A Group represents a collection of users who share expenses together. For example, some users use a Group to
    aggregate expenses related to a home. Others use it to represent a trip. Expenses assigned to a group are split among
    the users of that group. Importantly, two users in a Group can also have expenses with one another outside of the Group.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - Group
  tags_raw:
  - groups
  properties:
  - type: OpenAPI
    url: openapi/splitwise-groups-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-notifications-api
  name: Splitwise Notifications API
  description: The notifications API from Splitwise — 1 operation(s) for notifications.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - Notification
  tags_raw:
  - notifications
  properties:
  - type: OpenAPI
    url: openapi/splitwise-notifications-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-other-api
  name: Splitwise Other API
  description: The other API from Splitwise — 2 operation(s) for other.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags: []
  tags_raw:
  - other
  properties:
  - type: OpenAPI
    url: openapi/splitwise-other-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
- aid: splitwise:splitwise-users-api
  name: Splitwise Users API
  description: Resources to access and modify user information.
  humanURL: https://dev.splitwise.com/
  baseURL: https://secure.splitwise.com/api/v3.0
  tags:
  - User
  tags_raw:
  - users
  properties:
  - type: OpenAPI
    url: openapi/splitwise-users-api-openapi.yml
  - type: Conventions
    url: conventions/splitwise-conventions.yml
  - type: ErrorCatalog
    url: errors/splitwise-problem-types.yml
  - type: DataModel
    url: data-model/splitwise-data-model.yml
common:
- url: https://blog.splitwise.com/feed/
  type: BlogRSS
- type: Overlay
  url: overlays/splitwise-api-overlay.yaml
- type: Authentication
  url: authentication/splitwise-authentication.yml
- type: OAuthScopes
  url: scopes/splitwise-scopes.yml
- type: Conventions
  url: conventions/splitwise-conventions.yml
- type: ErrorCatalog
  url: errors/splitwise-problem-types.yml
- type: DataModel
  url: data-model/splitwise-data-model.yml
- type: Conformance
  url: conformance/splitwise-conformance.yml
- type: Lifecycle
  url: lifecycle/splitwise-lifecycle.yml
- type: StatusPage
  url: https://status.splitwise.com/
- type: Packages
  url: packages/splitwise-packages.yml
- type: X-MCPServerCandidate
  url: mcp/splitwise-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: LLMsTxt
  url: llms/splitwise-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: WellKnown
  url: well-known/splitwise-well-known.yml
- type: SecurityTxt
  url: well-known/splitwise-security.txt
- type: VulnerabilityDisclosure
  url: security/splitwise-vulnerability-disclosure.yml
- type: Security
  url: security/splitwise-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/splitwise-domain-security.yml
- type: DeveloperPortal
  url: https://dev.splitwise.com/
- type: Documentation
  url: https://dev.splitwise.com/
- type: APIReference
  url: https://dev.splitwise.com/
- type: SignUp
  url: https://secure.splitwise.com/apps
- type: Blog
  url: https://blog.splitwise.com/
- type: TermsOfService
  url: https://www.splitwise.com/terms
- type: PrivacyPolicy
  url: https://www.splitwise.com/privacy
- type: Website
  url: https://www.splitwise.com
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 15
  pass: local-v1

Splitwise API — frequently asked questions

Does Splitwise have an API?

Yes. APIs.io lists 7 APIs from Splitwise, including Splitwise Comments API, Splitwise Expenses API and Splitwise Friends API, and 4 more.

Is there an OpenAPI specification for the Splitwise API?

Yes. APIs.io indexes 7 OpenAPI specifications for Splitwise, each linked for download from this page.

How do I authenticate with the Splitwise API?

Splitwise documents its authentication (http/oauth2 · 2 schemes). The details are profiled on APIs.io as Splitwise Authentication.

Is the Splitwise API ready for AI agents?

Splitwise has a Kin Score of 40.5 out of 100 (developing) and an Agent Readiness score of 27.9 (agent-aware), scored by API Evangelist on 2026-11-06.

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